SPI_getargtypeid
Name
SPI_getargtypeid -- return the data type OID for an argument of
  a statement prepared by 
SPI_prepareSynopsis
Oid SPI_getargtypeid(SPIPlanPtr plan, int argIndex)
Description
   SPI_getargtypeid returns the OID representing the type
   for the argIndex'th argument of a statement prepared by
   SPI_prepare. First argument is at index zero.
  
Arguments
- SPIPlanPtr plan
       prepared statement (returned by SPI_prepare)
     
- int argIndex
       zero based index of the argument
     
Return Value
    The type OID of the argument at the given index.
    If the plan is NULL or invalid,
    or argIndex is less than 0 or
    not less than the number of arguments declared for the
    plan,
    SPI_result is set to SPI_ERROR_ARGUMENT
    and InvalidOid is returned.